Mj. Ledocq et al., ELECTRON NUMBER DENSITY-FLUCTUATIONS NEAR THE PLASMAPAUSE OBSERVED BYTHE CRRES SPACECRAFT, J GEO R-S P, 99(A12), 1994, pp. 23661-23671
Large quasi-periodic fluctuations in the electron number density are o
ften encountered near and inside the plasmapause by the CRRES satellit
e. A power spectral analysis reveals electron density fluctuations wit
h frequencies ranging from 2 mHz to approximately 61 mHz. Plasma densi
ty irregularities in the outer plasmasphere sometimes have power spect
ral slopes near -5/3, which suggest the presence of well-developed two
-dimensional magnetohydrodynamic turbulence. Quasi-periodic fluctuatio
ns have been found outside the plasmasphere with spatial scales along
the orbit path of approximately 750 km. A statistical analysis shows t
hat the density fluctuation amplitudes are largest between L = 3 and L
= 6, the region in which the plasmapause is located. The density fluc
tuation amplitudes decrease with increasing L shell for L > 6. Normali
zed fluctuation amplitudes greater than 10% are found in only 25% of t
he available data of this study. A significant magnetic local time dep
endence cannot be found due to incomplete data availability during the
9.00 to 14.99 MLT and the 15.00 to 20.99 MLT sectors.